A074025 - OEIS

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A074025

Numbers n such that a triplewhist tournament TWh(n) exists.

1, 4, 8, 16, 99999999999999999999 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	COMMENTS	`The term a(5) = 99999999999999999999 is a fake, inserted to prevent this sequence being incorrectly returned by Superseeker. Of course it will be replaced by the correct value, once that is determined.` `The present state of knowledge, quoting from Ge & Lam and the link below, is that a TWh(n) exists iff n == 0 or 1 (mod 4), except for n = 5, 9, 12 and possibly excepting n in {17, 57, 65, 69, 77, 85, 93, 117, 129, 153}.` `After 16, the sequence continues 17?, 20, 21, 24, 25, 28, 29, 32, 33, 36, 37, 40, 41, 44, 45, 48, 49, 52, 53, 56, 57?, ...`
	REFERENCES	`G. Ge and C. W. H. Lam, Some new triplewhist tournaments TWh(v), J. Combinat. Theory, A101 (2003), 153-159.`
	LINKS	`Harri Haanpaa and Petteri Kaski, The near resolvable 2-(13,4,3) designs and. thirteen-player whist tournaments, [shows that no TWh(13) exists]`
	CROSSREFS	`Sequence in context: A038110 A130436 A090804 * A031462 A045066 A151911` `Adjacent sequences: A074022 A074023 A074024 * A074026 A074027 A074028`
	KEYWORD	`nonn,more,nice`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com), Oct 16 2003`
	EXTENSIONS	`Of course this entry is much too short. But I have included it in the hope that this will encourage someone to settle the question of whether a(5) is 17 or 20 - i.e. does a TWh(17) exist?` `Link supplied by Jon Schoenfield, Aug 01 2006`

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Last modified February 15 03:11 EST 2012. Contains 205694 sequences.